One of the more notorious features of Restoration
and eighteenth-century London was the Fleet, which was, at various times
in its long history, a stream, a canal, a gutter, and a closed sewer.
The neighbourhood around the banks of the Fleet was perennially squalid,
poor, and unfashionable, and the river itself was very nearly always treated
as a kind of embarrassment by Londoners.

Although once apparently commodious
enough to accommodate a fair degree of light shipping, the Fleet had,
by the 16th century, become shallow and slow-running; easily obstructed,
it filled with rubbish and became intolerably smelly. Attempts throughout
its history to clean it up, and prohibit its use as a waste dump, nearly
always proved futile; one such ineffectual attempt was made in 1652.

The rebuilding of London following
the Great Fire presented an opportunity to remodel the Fleet entirely:
Sir Christopher Wren had, as part of his plan for the rebuilding of London,
proposed widening it, and laying out broad embankments on either side.
Wren's ambitious plans were not fully realized, but the lower part of
the river was, under his supervision, and that of Robert Hooke, dredged
and widened into a canal, which was completed in October of 1674. The
river was straightened, and provided a greater width of up to 50 feet,
from Holborn down to the Thames; the banks were levelled with brick and
stone, and provided with new wharves, while the section of the river north
of Holborn to the City wall was covered over.

Unfortunately, the new Fleet Canal
was apparently little used for its new intended purpose, and the lack
of commercial traffic employing it doomed it; it soon reverted to its
earlier function as a dump for raw sewage and rubbish. In 1733, it was
arched over from Holborn Bridge to Fleet Bridge, the river running under
what is now Farringdon Road. In 1766, after a drunken butcher who had
fallen in the sludge froze to death, the remainder of the Fleet was arched
over: it became, and indeed remains, a part of London's underground sewer
system.